PTEN and melanoma: Importantly, the combination treatment was found to decrease the activation/phosphorylation of oncogenic signaling pathways, 3-phosphoinositide-dependent protein kinase-1 (PDK1), and AKT and increase the activation of the tumor suppressive gene, phosphatase and tensin homolog (PTEN) expression, which explains the enhanced sensitivity of vemurafenib and melatonin towards melanoma [11].